Crucible-furnace.



W. MILLER.

URUUIBLE FURNAGE.

APPLIGATION FILED JUNE 2, 1909.

Patented Oct. 11,1910;

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TinrTnn sTaTns PATENT orrion WILLIAM MILLER, OF WELLINGTON, ENGLAND.

CRUCIBLE-FURNACE.

- Application filed June 2, 1909.

To all whom it may concern:

Be it known that I, VILLIAM MILLER, a subject of the King of the UnitedKingdom of Great Britain and Ireland, and residing at Vellington, Salop,England, have invented a certain new and useful Improvement in Crucibledurnaces, of which the following is a specification.

This invention relates to crucible furnaces for melting steel and othermetals and it consists firstly of an improved construction of suchfurnaces in which the primary air supply for combustion of the coke orother fuel used to heat the crucible is heated in an arrangement ofregenerative flues disposed contiguous to the waste gas flues and alsosupplemental air so heated is supplied to the furnace over the fuel toeffect complete combustion of the fire gases arising from the fuelaround the crucible.

Other features of the invention appear from the following description.

In the accompanying drawings, Figures 1 and 2 are vertical sections atright angles to each other and Fig. 3 is a horizontal section of acrucible furnace constructed in accord ance with the invention.

Referring to the drawings, the crucible furnace may be of ordinary formhaving a metallic casing A with a fire clay lining B and a bottom grateC, supported on brackets C through which grate the heated air has accessand the ash from the fuel drops into an ash-pit D below. The bottom ofthe ash space is formed by a water tray or trough E having a projectingflangeFresting on the brickwork setting of the furnace and formed withperforations or openings G in conjunction with perforations or openingsin the brackets O for the passage around it of the heated air which isdrawn through the branches 72, of a regenerator flue H in brickwork atthe rear of the furnace and passes up to the under side of the furnacegrate C, and, if desired, passes up to the upper side of )t he grate Cby passages f, f and ports 7,

The hot waste gases from the furnace, which is closed by a cover I,escape to and through a waste gas flue or flues J, K, contiguous to theair fiueHand thence toamain flue L leading to the chimney so that theair supply is heated. A portion of the air so heated is diverted eitherthrough suitable pipes or through passages M which may be provided withregulating valves M toward Specification of Letters Patent.

Patented Oct. 11, 1910.

Serial No. 499,755.

the upper part of the furnace into which it passes by way of ports N ator over the fuel level and serving as a supplemental air supply ignitesthe unconsumed gases; while water vapor rising from the water tray ortrough E which is supplied by a drip pipe 0 enters with the primary airsupply through the furnace grate G and generates combustible gas whichis consumed on meeting with the supplemental air supply.

The crucible or crucibles Q (Figs. 1 and 2) placed in the furnace may beremovable and may rest on a support on the bottom grate O as is usual,but by preference, and as shown in Fig. 4, the crucible Q is made afixture and instead of being removed from the furnace to pour off themolten metal is made with a tapping hole 9 and spout g at its lower endfrom which the metal is drawn, thus avoiding loss by breakage due tohandling of the crucible. It will be understood that the furnaces may beadapted to accommodate any number of crucibles.

By the arrangements described the regeneration of the air is continuousand increases in intensity as the fines become hotter. A hightemperature can be attained in a short time and thereafter maintained,while great saving of fuel is effected by the introduction ofsupplemental air to consume the gases in the furnace which wouldotherwise go to waste.

The flue H may serve as a chamber which supplies the air from the valvecontrolled air inlet pipe R in a partially heated condition and whichchamber may be divided or baffled as shown at B (Fig. l) to extend theheating surface, or the air may be passed through a coil of pipingplaced in the flue H or other heating chamber. The draft may either beforced or natural.

Access to the flues and ashpit is had through removable doors or plates(Z which may be luted with clay or otherwise made air-tight.

Having now described my invention what I claim and desire to secure byLetters Patent of the United States is A crucible furnace comprising afire grate and crucibles sup-ported thereon, the walls of said furnacebeing built to provide waste gas flues communicating with each other,one leading from the upper end of the furnace, and a regenerative fluedisposed between said waste gas flues, said regenerative flue leading tothe underside of the fire grate, and vertical passages in communica- Intestimony whereof I have signed my tion With the regenerative flue andprovlded name to this specificatlon 1n the presence or 10 With portsbranchlng therefrom into the 111 tWo subscrlblng wltnesses.

terior of the furnace at points adjacent the lower ends of thecrucibles, and ports VILLIAM MILLER branching therefrom into theinterior of the Vitnesses:

furnace at points adjacent the upper ends l/VALLAGE CRANSTONFAIRWEATHER, of the crucibles, substantially as described. J OHNMOCLEARY, Jr.

